Caprine arthritis encephalitis virus (CAEV) is a retrovirus belonging to the lentivirus genus that also includes the human immunodeficiency virus (HIV). CAEV may be transmitted to humans by goat milk consumption. It has been suggested that CAEV may also be involved in the immunological protection process against HIV, but this has not been demonstrated. Here we identified serological reactivity against CAEV gp135 in children who consumed goat milk. Thirty sera samples from children (males between 6 and 16 years of age) who regularly consumed goat milk and a negative control of 30 serum samples from children (males between 6 and 12 years) with no previous contact with goats or goat dairy products were used. All sera were tested by Western blot against CAEV antigens. There were 18/30 serum samples from goat milk consumers that were reactive to CAEV gp135, and one reacted against gp50 simultaneously; none of the 30 serum samples from nonconsumers of goat dairy products reacted to viral proteins. These results showed that the positive response to gp135 may be the result of a repetitive stimulation without viral replication or the result of CAEV replication in humans. CAEV gp135 is codified by the env gene located on the viral particle surface as well as gp50. Moreover, there are similarities between CAEV gp135 and HIV-1 gp120, so there is a possibility that CAEV replicates in humans and may participate in immunological cross-phenomena, but this should be further studied.